The present invention relates generally to an improved adjustable mounting plate for telescopic struts employed in motor vehicle suspensions, and more particularly to an adjustable strut mounting plate for those motor vehicles utilizing a suspension support mechanism with a telescopic strut assembly linking the chassis to the wheel assembly and being mounted concentrically within a helical coil spring support. The adjustable strut mounting plate of the present invention finds particular application in those vehicle suspensions equipped with McPherson-type struts. This type of suspension finds wide application in a large variety of motor vehicles, and is widely used as a component in the front suspension mechanisms of conventional automotive vehicles.
Strut suspensions typically employ a telescopic strut which includes a shock absorber arrangement or other motion dampener, and is used as a primary component for positionably mounting the bottom end of a steerable wheel assembly which includes a front wheel of a front-wheel drive automobile. In this arrangement, the strut is positioned concentrically within the normal helical main suspension spring, with the top of the strut being located and secured within a strut-receiving housing or "tower" which is formed integrally within the chassis of the vehicle to position the wheel assembly relative to the chassis. Typically, the strut tower is physically located within the engine compartment and the top of the strut has a mounting location arranged generally concentrically within the strut tower. In order to couple the upper end or top of the strut to the tower, the strut mounting components are secured within a strut mounting plate. The strut mounting plate is generally in the form of a flat annular plate, with a central opening into which the top of the strut is received and tightly secured. Because the strut is frequently subjected to shock loading during normal use, the top of the strut is coupled through the cut-out in the annular plate with a coupler surrounding a resilient grommet assembly, such as one comprising a durable rubber of relatively high durometer. The mounting plate also has fixed bores formed therein through which fastener bolts are received in mating relationship within the corresponding bores formed in the strut tower. The details of such assemblies are, of course, well known to those of skill in the art.
These strut assemblies have the disadvantage of providing only limited adjustability for alignment correction. Because of the nature of ordinary wear and tear, the loading to which the suspension system is put during normal use, and because of the occurrence of frequent minor impacts with solid objects due to conventional usage, alignment characteristics and adjustment will be found to vary from those as originally set by the vehicle manufacturer and beyond correction from the limited capability of factory systems. Due to these variations caused by and resulting from normal usage of the vehicle, capabilities to restore to proper alignment adjustment parameters are frequently lost. In order to maintain safety, reliability, and drivability, it is necessary to adjustably reposition the top end of the strut within the strut tower from time-to-time to restore the wheel assembly to the desired readings, particularly the camber setting. The improved mounting plates of the present invention enable the technicians to provide significant corrections in camber adjustments, with this expansion of correction capability being provided with a plate suitable for both right wheel and left wheel uses.
In typical strut assemblies, the lower end of the strut is coupled to the wheel assembly portion of the vehicle, with the mounting point generally being through a mechanism coupled directly to the steering knuckle. This lower mounting point is fixed in its location, and is generally not subject to relocation. The steering knuckle is, in turn, coupled to both the control arms and the distal or terminal end of the drive mechanism for a front-wheel drive vehicle.
Since the mounting point at the lower end of the strut is generally non-adjustable, there is need for an application wherein the upper end of the strut may, be reliably relocated in order to adjust alignment parameters, particularly the camber position and reading of the front wheels of the vehicle. While certain devices for this application have been proposed in the past, these applications have not been highly useful because of their limited application to either right hand or left hand use, and because of the lack of a relatively fixed adjustment mounting point. When the mounting point is fixed, the range of adjustment is extremely limited. Additionally, the devices proposed in the past frequently require alteration of either the mounting points, and/or cause significant repositioning of the wheel assembly because of their configuration. When the configuration causes a significant shift in the positioning of the strut mounting, adverse affects may result in the overall stability, steerability, and drivability of the vehicle. The device of the present invention provides an adjustable strut mounting plate which has fixed mounting bores therein to render it adaptable for both right hand and left hand mounts, and at the same time, providing a predetermined fixed location for positionably adjusting the camber setting for the wheel assembly of strut-type suspension mechanisms without requiring other adjustments or alterations in the alignment system.